AT&T announced today (pdf) the welcome addition of six new areas covered by its 4G LTE network. The carrier also reminded us that 77 more markets are slated to receive some 4G love as soon as this summer.

When it comes to 4G LTE coverage, AT&T is only outclassed by Verizon; Big Red's LTE data network currently services 486 markets across the United States. AT&T, by comparison, covers 182 markets after including today's six additions; however, AT&T likes to tout its widely available HSPA+ network as a suitable fallback where 4G LTE remains unavailable.

AT&T boldly claims it has the "nation's fastest 4G LTE network" and that it operates the nation's largest "4G" (non-LTE) network -- this of course includes its slower but expansive HSPA+ coverage.

Other carriers, namely Sprint and T-Mobile are far behind AT&T and Verizon in terms of 4G LTE coverage. However, both companies have continued to invest in building out their high-speed data infrastructure. T-Mobile just recently announced the first time it's offering 4G LTE coverage (12 markets so far) while Sprint already covers more than 70 itself.